/*
 * Copyright 2014 http://Bither.net
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.bither.util;

import java.util.concurrent.Executor;

public class WalletEventListenerExecutor implements Executor {
	private static WalletEventListenerExecutor instance;

	public static WalletEventListenerExecutor instance() {
		if (instance == null) {
			instance = new WalletEventListenerExecutor();
		}
		return instance;
	}

	private Runnable penddingCommand;
	private RunningThread runningThread;

	private WalletEventListenerExecutor() {
	}

	private int executedCount;
	private int abortedCount;

	@Override
	public void execute(Runnable command) {
		if (runningThread != null && runningThread.isAlive()) {
			if (penddingCommand != null && penddingCommand != command) {
				abortedCount++;
			}
			penddingCommand = command;
			return;
		}
		runningThread = new RunningThread(command);
		runningThread.start();
	}

	private class RunningThread extends Thread {
		private Runnable currentRunnable;

		public RunningThread(Runnable runnable) {
			currentRunnable = runnable;
		}

		@Override
		public void run() {
			executedCount = 0;
			abortedCount = 0;
			while (currentRunnable != null) {
				if (currentRunnable == penddingCommand) {
					penddingCommand = null;
				}
				currentRunnable.run();
				executedCount++;
				currentRunnable = penddingCommand;
			}
			LogUtil.d("WalletEvent", "WalletEvent executed: " + executedCount
					+ " , aborted: " + abortedCount);
			runningThread = null;
		}
	}
}
